Hmm, I dunno... I kinda have the opposite reaction, that with a quality tube amp, the HD800 might have a really deep soundstage, more holographic imaging. But I do get where you're coming from... I've definitely heard crappier tube headphone amps than SS amps, but when glass is done right, nothing else compares. I, for one, look forward to trying my Leben CS600 with it first. Or, as I said, the OTL/SET config of WA2 would complement the Senns well... or the WA5s!